Narrow-Band Imaging in oncologic otorhinolaryngology: State of the art

Characterization of irradiated mucosa using confocal laser endomicroscopy in the upper aerodigestive tract

PURPOSE

Confocal laser endomicroscopy (CLE) enables a real time in-vivo optical biopsy of the upper aerodigestive tract. Previous studies demonstrated its potential in identifying malignant tissue, but none examined mucosa treated with radiotherapy. This study characterizes the appearance of irradiated mucosa using CLE.

METHODS

We recorded 58 CLE sequences (860 s, 6,884 frames) in 10 patients previously treated with radiotherapy for upper aerodigestive tract tumors. A corresponding tissue biopsy (formalin-fixed, H&E stained) was taken as the reference standard for each sequence. We analyzed each sequence regarding differences from normal mucosa and characterized irradiated mucosa in CLE.

RESULTS

Irradiated mucosa in CLE exhibits irregular tissue architecture. Radiation induces DNA damage, apoptosis, and tissue inflammation, leading to hyperkeratotic and fibrotic tissue. Consequently, CLE showed a wider range of cellular morphologic and tissue structural aberrancies, in comparison to normal, non-irradiated mucosa. In addition to regular honeycomb-like patterns, the tissue displayed uneven, blurry, and cell-rich areas. Irradiated mucosa appears more irregular and variable in CLE than radiation-naïve mucosa.

CONCLUSION

Irradiated mucosa can be differentiated from healthy tissue using CLE, but its higher baseline morphological variability may mimic malignancy. Further research is needed to clarify its impact on tumor detection and refine existing scoring systems.

Narrow-band imaging offers a shorter menstrual bleeding time and a longer remission for hysteroscopic surgery in symptomatic post-cesarean scar diverticulum compared to white light

BACKGROUND

Narrow-band imaging (NBI) is a novel endoscopic imaging technology that improves the visibility of capillaries. The aim of this study was to evaluate the efficacy of NBI hysteroscopic excision in symptomatic post-cesarean scar diverticulum (PCSD) patients compared to conventional white light (WL) hysteroscopy.

METHOD

A total of 73 patients with symptomatic PCSD between January 2014 and December 2018 were enrolled. The enrolled patients were stratified into NBI and WL groups according to whether they received NBI or WL hysteroscopy. Postoperative menstrual patterns at one, six, and 12 months after the operation were collected and compared between the NBI and WL groups.

RESULTS

A total of 32 patients underwent NBI hysteroscopy (NBI group), while 41 patients received WL hysteroscopy (WL group). The symptom-free remission rates in the NBI group were significantly higher than in the WL group at six months and 12 months post-hysteroscopy. At the final follow-up, the menstrual bleeding duration in the NBI group was significantly shorter than in the WL group.

CONCLUSION

The use of NBI hysteroscopy in treating symptomatic PCSD resulted in shorter menstrual bleeding days and longer symptomatic remission compared to conventional WL hysteroscopy.

Investigating the key principles in two-step heterogeneous transfer learning for early laryngeal cancer identification

Data scarcity in medical images makes transfer learning a common approach in computer-aided diagnosis. Some disease classification tasks can rely on large homogeneous public datasets to train the transferred model, while others cannot, i.e., endoscopic laryngeal cancer image identification. Distinguished from most current works, this work pioneers exploring a two-step heterogeneous transfer learning (THTL) framework for laryngeal cancer identification and summarizing the fundamental principles for the intermediate domain selection. For heterogeneity and clear vascular representation, diabetic retinopathy images were chosen as THTL's intermediate domain. The experiment results reveal two vital principles in intermediate domain selection for future studies: 1) the size of the intermediate domain is not a sufficient condition to improve the transfer learning performance; 2) even distinct vascular features in the intermediate domain do not guarantee improved performance in the target domain. We observe that radial vascular patterns benefit benign classification, whereas twisted and tangled patterns align more with malignant classification. Additionally, to compensate for the absence of twisted patterns in the intermediate domains, we propose the Step-Wise Fine-Tuning (SWFT) technique, guided by the Layer Class Activate Map (LayerCAM) visualization result, getting 20.4% accuracy increases compared to accuracy from THTL's, even higher than fine-tune all layers.

The added value of narrow band imaging in Sinonasal tumour resection and surveillance: Our experience

BACKGROUND & PURPOSE

Narrow Band Imaging (NBI), developed by Olympus Medical Systems, has played a role in diagnosing digestive tract lesions and cancers, diagnosing and characterizing bladder cancers during cystoscopy and in the diagnosis and management of Head and Neck cancers. We aim to explore the potential use of NBI in the diagnosis, management, and follow-up of sinonasal tumours.

METHODS

We present a series of cases treated at our institution, where NBI played a crucial role in the diagnosis, surgical management, intraoperative decision-making, and follow-up. The cases include a patient with sinonasal lymphoma, 2 patients with sinonosal malignant melanoma and a patient with olfactory neuroblastoma.

RESULTS

In our experience, NBI proved beneficial not only in detecting otherwise unseen nasal lesions but also in targeted biopsies and intraoperative planning, on some occasions altering the course of treatment. NBI may also be a simple, inexpensive surveillance method for detecting sinonasal tumours recurrence after excision.

CONCLUSION

While there are limitations to its use, there is potential for NBI to be of significant use in rhinology practice, reducing morbidity and tumour recurrence rates and streamlining the diagnostic and surveillance process.

Imaging Modalities for Head and Neck Cancer: Present and Future

Several imaging modalities are utilized in the diagnosis, treatment, and surveillance of head and neck cancer. First-line imaging remains computed tomography (CT); however, MRI, PET with CT (PET/CT), and ultrasound are often used. In the last decade, several new imaging modalities have been developed that have the potential to improve early detection, modify treatment, decrease treatment morbidity, and augment surveillance. Among these, molecular imaging, lymph node mapping, and adjustments to endoscopic techniques are promising. The present review focuses on existing imaging, novel techniques, and the recent changes to imaging practices within the field.

Early-stage hypopharyngeal squamous cell carcinoma treated with radical radiotherapy at a uniform dose of 70 Gy in 35 fractions: a single-center study

INTRODUCTION

Hypopharyngeal squamous cell carcinoma (HSCC) is often undetected until advanced stages, which contributes to poor survival rates. Recent advances in diagnostic techniques have enhanced the feasibility of early detection, and this study evaluated the efficacy and safety of radical radiotherapy that specifically targets early stage HSCC.

METHODS

This retrospective cohort study consecutively analyzed patients with clinical stage I or II HSCC between December 2008 and February 2023. These patients underwent radical radiotherapy with a uniform dose of 70 Gy delivered in 35 fractions to the primary site, followed by elective nodal irradiation. We assessed clinical outcomes, including overall survival (OS), disease-free survival (DFS), and 5-year locoregional control (LRC). Multivariate analyses were performed to identify the independent prognostic factors for OS.

RESULTS

The 5-year OS rate of the entire cohort was 80.7% (95% confidence interval [CI] = 66.5-89.4%), with no significant difference between patients with clinical stage I and II HSCC. Stratified by subsite, the 5-year OS for pyriform sinus, posterior pharyngeal wall, and postcricoid region were 81.6, 68.2, and 100%, respectively. The ECOG-Performance status (PS) was identified as an independent risk factor for OS (hazard ratio [HR] = 8.457; 95% CI 1.325-53.970; p = 0.024). DFS at 5 years was 66.4%, with local recurrence being the most frequent, and LRC rate at 5 years was 79.3%. Acute and late-phase toxicities were predominantly mild to moderate, with no grade 3 or higher toxicities reported.

CONCLUSION

This study supports radical radiotherapy as an effective approach for optimal tumor control in patients with early stage HSCC. Despite the limitations of this study, including its retrospective design and single-center confinement, our results revealed the effectiveness and feasibility of radical radiotherapy in the management of early stage HSCC.

Accuracy of Narrow-Band Imaging-Guided Histopathology and Ki-67 Index in Head and Neck Carcinoma

As per Globocan 2012, every year the incidence of head and neck cancer is 683235/1000000 with a mortality of around 375665/1000000 thus being the sixth cause of cancer death throughout the world. Head and neck cancer includes cancer of the nasopharynx, oropharynx, hypopharynx, larynx, and oral cavity. Early diagnosis of head and neck cancer is very challenging, hence detecting mucosal lesions at an early stage decreases mortality thereby improving overall survival, disease-free survival, and quality of life. Out of different diagnostic modalities, narrow-band imaging (NBI) combined with endoscopic techniques can provide a promising diagnostic tool in detecting early lesions of head and neck cancer. Numerous studies have shown that Ki-67 is a good prognostic marker in oral cancers. Our study aims to evaluate the diagnostic accuracy of NBI and combine the Ki-67 index to diagnose head and neck cancer.

Materials and Methods

All patients were first examined under white light and then under NBI endoscopy, and a biopsy was obtained from suspected lesions and sent for histopathological examination (HPE) and Ki-67 index.

Results

Eighty patients were examined out of which, 68 patients having lesions in the oral cavity, oropharynx, larynx, and hypopharynx were examined. The rate of detecting cancerous lesion by white light and NBI were respectively 92% and 100% for oral cavity lesions, 69% and 100% for oropharyngeal lesions, 38% and 100% for hypopharyngeal lesions, and 37% and 100% for laryngeal carcinoma. However, we have found no significant difference in detecting T2-T4 tumors. Hence, we concluded that NBI mode can be a significantly better diagnostic tool than white light mode in detecting early mucosal cancer in head and neck cancer.

Conclusion

We have concluded that NBI combined with Ki-67 estimation is a very promising tool that helps in the early diagnosis of mucosal lesions in head and and neck cancer.

Application of narrow band imaging in the diagnosis of pharyngeal tumors

BACKGROUND

Narrow-band imaging (NBI) endoscopy is used in various tumor detection and is important in detecting early tumors.

OBJECTIVE

To explore the application value of NBI endoscopy in diagnosing pharyngeal tumors.

MATERIAL AND METHODS

Ninety-one patients with pharyngeal masses who attended the Department of Otorhinolaryngology, Head and Neck Surgery in Gansu Provincial Hospital from January 2023 to February 2024 were selected, and NBI and white light (WL) endoscopy were applied to examine the pharynx and the relationship between the two was observed. SPSS 25.0 software was used for statistical analysis.

RESULTS

The sensitivity of NBI endoscopy for diagnosing laryngeal malignant lesions was 92.0 %, the specificity was 93.0 %, the positive predictive value was 88.5 %, and the negative predictive value was 95.2 %, with a high degree of concordance between the results of NBI endoscopy and the pathology; WL endoscopy had a sensitivity of 64.0 %, a specificity of 76. 7 %, a positive predictive value of 61.5 %, and a negative predictive value of 78.6 %, with WL endoscopic findings had moderate concordance with pathology. The diagnostic accuracy of NBI endoscopy was higher than that of WL endoscopy for both benign and malignant lesions and precancerous lesions.

CONCLUSION

NBI endoscopy can detect laryngeal cancer lesions more accurately.

Pathological Insights on Polypropylene Mesh Complications From Laparoscopic Sacrocolpopexy: A Case Series

Background The use of polypropylene mesh in laparoscopic sacrocolpopexy (LSC) is a common treatment for pelvic organ prolapse (POP). Despite its widespread application, postoperative complications such as mesh pain and infection sometimes necessitate the removal of the mesh. However, it remains unclear in which cases mesh removal is warranted. Our research focused on the pathological changes at the sacral fixation point of the mesh. We sought to evaluate the pathological alterations of the sacral mesh removed through an innovative approach of transvaginal natural orifice transluminal endoscopic surgery (vNOTES). Methods This retrospective study included nine patients who underwent mesh removal surgery at the Yokosuka Urogynecology and Urology Clinic in 2023. Extraction surgery was performed using vNOTES with the GelPoint Access Platform (Applied Medical JAPAN HEADQUARTERS, Tokyo, Japan). Non-ablative Erbium YAG and Neodymium YAG lasers (RenovaLase, SP Dynamis; Fotona d.o.o., Ljubljana, Slovenia) were utilized for persistent stress urinary incontinence, fecal incontinence, vaginal erosion, and bleeding after surgery. Patients were categorized based on mesh fixation conditions, including unintended mesh overlap (Group I), excessive traction (Group II), and signs of mesh aging (Group III). This categorization helped to understand the distinct pathological outcomes associated with each condition. Results Pathological findings from the mesh removed via vNOTES varied significantly across the groups. In Group I, characteristic large vacuole formation and accumulation of atypical giant cells were observed, attributed to mesh overlap. Group II presented with vacuole formation, fiber degradation, and tissue destruction as a result of excessive mesh traction. In Group III, the aging of the mesh was marked by cracks in the surrounding tissues and granuloma formation. These detailed observations provide crucial insights into the underlying causes of mesh-related pain and other complications, highlighting the complexity of bodily responses to mesh implants. Conclusion This study demonstrated the effectiveness of vNOTES for polypropylene mesh removal in patients with post-LSC complications, resulting in significant pain reduction. Pathological analysis revealed that mesh-related issues stem from the surgical techniques, mesh properties, and long-term bodily reactions. These findings provide valuable insights for improving mesh design and POP treatment strategies. Despite the technical challenges, vNOTES is recommended for mesh removal in patients with pain. Additionally, the combination of UEL, VEL, targeted laser irradiation, AEL, and Nd:YAG laser treatments showed promising results in managing post-mesh removal complications such as stress urinary incontinence, vaginal erosion, bleeding, and fecal incontinence, offering hope for improved patient outcomes.

A Rare Case of Adult Vocal Cord Hemangioma: A Case Report and Literature Review

Infantile laryngeal hemangiomas are relatively common. However, adult vocal cord hemangiomas are extremely rare. A 46-year-old woman was referred to our department for hoarseness, which continued for 18 months. A laryngeal fiberscope revealed a small protuberant tumor resembling a polyp on her right vocal cord, and the narrow-band imaging showed abundant vascularity. Laryngeal microsurgery with a cold instrument under general anesthesia completely resected the tumor on the vocal cord. Histopathologically, the resected tumor consisted of vessels with thick walls and was diagnosed as a cavernous hemangioma of the vocal cord. After the surgery, she has never complained of hoarseness and has had no local recurrence for six months.

Implementation of Routine Endoscopy with Narrow Band Imaging in the Evaluation of Oral and Upper Airways Lesions in Oral Chronic Graft-Versus-Host Disease: A Preliminary Study

(1) Background: The aim of our study is to investigate the main oral lesion patterns in patients with oral graft-versus-host disease and to describe and validate the use of endoscopy enhanced with narrow-band imaging (NBI) as a personalized, reliable and user-friendly tool for the early detection of oral potentially diseases. (2) Methods: We retrospectively evaluated the medical records of 20 patients with chronic GVHD and with oral manifestations, who were referred to our “Interdisciplinary Center for Oropharyngeal Pathology (CIPO)” from January 2017 to July 2022. (3) Results: Data on GVHD, oral localization and NBI endoscopic evaluation are collected. A total of six mucositis, one mucosal erythematous change, ten lichenoid-like changes, eight erosive lesions, one leukoplakia, two erythroplakia and two case of blisters were observed. Two vascular abnormalities were seen with NBI, leading to one excisional biopsy. The patient was diagnosed with squamous cell carcinoma. (4) Conclusion: Our study is the first to highlight the relevance of the routine use of endoscopy with NBI in patients with oral chronic GVHD. We highlighted its role as a reliable, reproducible, easy-to-use and tailor-made tool in the follow-up of those patients and to allow an earlier identification of aberrant neoangiogenesis related to oral potentially malignant disorders and oral cancer.

Videolaryngoendoscopic and Stroboscopic Evaluation in Predicting the Malignancy Risk of Vocal Fold Leukoplakia

Background: Vocal fold leukoplakia (VFL), despite our knowledge of its etiopathogenetic factors, and the development of laryngeal visualization, remains a diagnostic and therapeutic challenge. Objective: This research aimed to explore the efficacy of clinical and morphological feature identification in videolaryngoendoscopy (VLE) using a three-tier classification, and videolaryngostroboscopy (VLS) in predicting the risk of VFL malignant transformation. Material and Methods: We examined 98 patients with VFL by flexible endoscopy under VLE and VLS. Morphological characteristics of 123 lesions including the surface, margin, and texture were assessed; then, VFL was subdivided into three types: I—flat and smooth, II—elevated and smooth, and III—rough. Based on the histopathological findings, 76 (61.79%) lesions were classified as low- and 47 (38.21%) lesions as high-grade dysplasia. Results: The inter-rater agreement between two raters evaluating the VFL in VLE was almost perfect (Cohen’s kappa = 0.826; p < 0.00; 95%CI 0.748−0.904). In ROC curve analysis, the AUC difference between Rater I and Rater II was 0.024 (0.726 vs. 0.702). In multivariate analysis, high-risk VFL was positively related to unilateral plaque localization (p = 0.003), the type III VLE classification (p = 0.013), absence of a mucosal wave (p = 0.034), and a positive history of alcohol consumption (p = 0.047). In ROC analysis, VLE had an AUC of 0.726, with a high sensitivity of 95.7% and low specificity of 40.8%. The NPV was high, at 93.9%; however, the PPV was low, at 50%. The proposed logistic regression model including features significant in multivariate analysis showed lower sensitivity (80.9% vs. 95.7%) and lower NPV (86.2% vs. 93.9%); however, the specificity and PPV were improved (73.7% vs. 40.8% and 65.5% vs. 50.0%, respectively). Conclusions: The combination of clinical history with endoscopic (plaque morphology) and stroboscopic examination (mucosal wave assessment) can fairly estimate the degree of dysplasia in VFL and thus is recommended for use in clinical settings. The findings of this study can be used to guide the decision regarding immediate biopsy or watchful waiting.

Systematic classification of confocal laser endomicroscopy for the diagnosis of oral cavity carcinoma

INTRODUCTION

Confocal laser endomicroscopy (CLE) is an optical imaging technique that allows in vivo microscope-like images of the upper aerodigestive tract's mucosa in 1000-fold magnification. The assessment of morphological tissue characteristics for the correct differentiation between healthy and malignoma suspected mucosa requires strict evaluation criteria. This study aims to validate a score for oral cavity squamous cell carcinoma (OCSCC) diagnostic.

METHODS

We performed CLE and examined a total of twelve patients. All 95 sequences (778 s, 6224 images) originate from the area of the primary tumor 260 s, 2080 images) and unsuspicious mucosa of the oral cavity (518 s, 4144 images). Specimen were taken at corresponding locations and analyzed histologically in H&E staining as a reference standard. A total of eight examiners (four experienced and four inexperienced) evaluated the sequences based on a scoring system. The primary endpoints are sensitivity, specificity, and accuracy. Secondary endpoints are inter-rater reliability and receiver operator characteristics.

RESULTS

Healthy mucosa showed epithelium with uniform size and shape with distinct cytoplasmic membranes and regular vessel architecture. CLE of malignant cells demonstrated a disorganized arrangement of variable cellular morphology. We calculated an accuracy, sensitivity, specificity, PPV, and NPV of 88.7 %, 90.1 %, 87.4 %, 87.5 %, and 90.0 %, respectively, with inter-rater reliability and κ-value of 0.775, and an area under the curve of 0.935.

CONCLUSIONS

The results confirm that this scoring system is applicable in the oral cavity mucosa to classify benign and malignant tissue.

Image-guided surgery in oral cancer: toward improved margin control

PURPOSE OF REVIEW

The aim of this review is to discuss recent studies on the assessment of tumor extension and resection margins by different intraoperative techniques allowing for image-guided surgery of oral cancer.

RECENT FINDINGS

There are different in-vivo and ex-vivo intraoperative techniques to improve margin control of which intraoperative ultrasound and targeted fluorescence-guided resections have high potential clinical value and are closest to clinical implementation.

SUMMARY

In oral cancer surgery, resection margins, particularly deep margins, are often inadequate. Intraoperative frozen section does not improve resection margin control sufficiently. Specimen-driven intraoperative assessment for gross analysis of suspected margins reduces the amount of positive resection margins substantially but leaves still room for improvement. Mucosal staining methods, optical coherence tomography and narrow band imaging can only be used for superficial (mucosal) resection margin control. Spectroscopy is under investigation, but clinical data are scarce. Intraoperative ex-vivo imaging of the resection specimen by magnetic resonance and PET/computed tomography may be used to assess resection margins but needs more research. Intraoperative in-vivo ad ex-vivo ultrasound and targeted fluorescence imaging have high potential clinical value to guide oral cancer resections and are closest to clinical implementation for improved margin control.

Systematic interpretation of confocal laser endomicroscopy: larynx and pharynx confocal imaging score

OBJECTIVE

Development and validation of a confocal laser endomicroscopy (CLE) classification score for the larynx and pharynx.

METHODS

Thirteen patients (154 video sequences, 9240 images) with laryngeal or pharyngeal SCC were included in this prospective study between October 2020 and February 2021. Each CLE sequence was correlated with the gold standard of histopathological examination. Based on a dataset of 94 video sequences (5640 images), a scoring system was developed. In the remaining 60 sequences (3600 images), the score was validated by four CLE experts and four head and neck surgeons who were not familiar with CLE.

RESULTS

Tissue homogeneity, cell size, borders and clusters, capillary loops and the nucleus/cytoplasm ratio were defined as the scoring criteria. Using this score, the CLE experts obtained an accuracy, sensitivity, and specificity of 90.8%, 95.1%, and 86.4%, respectively, and the CLE non-experts of 86.2%, 86.4%, and 86.1%. Interobserver agreement Fleiss' kappa was 0.8 and 0.6, respectively.

CONCLUSIONS

CLE can be reliably evaluated based on defined and reproducible imaging features, which demonstrate a high diagnostic value. CLE can be easily integrated into the intraoperative setting and generate real-time, in-vivo microscopic images to demarcate malignant changes.

Comparison of Simultaneous Swallowing Endoscopy and Videofluoroscopy in Neurogenic Dysphagia

OBJECTIVE

In the evaluation of oropharyngeal dysphagia, instrumental procedures, for example, flexible endoscopic evaluation of swallowing or videofluoroscopic swallowing study, are essential to improve diagnostic accuracy for salient findings such as penetration, aspiration, or pharyngeal residue. To date, it is unclear which of the 2 methods represents the diagnostic gold standard. The aim of this study, therefore, was to compare videofluoroscopy and swallowing endoscopy during a simultaneous swallowing examination in a large cohort of patients with oropharyngeal dysphagia.

DESIGNS

Prospective observational study.

SETTING AND PARTICIPANTS

In this study, 49 patients with oropharyngeal dysphagia (mean age 70.0 ± 10.8 years) were evaluated using simultaneous swallowing endoscopy and videofluoroscopy. Furthermore, the effect of narrow-band imaging in swallowing endoscopy on the assessment of penetration and aspiration was investigated in a subgroup of 19 patients.

MEASURES

The Penetration-Aspiration Scale and the Yale Pharyngeal Residue Severity Rating Scale were rated independently based on both modalities.

RESULTS

Both modalities showed a high correlation between penetration, aspiration, and pharyngeal residue. Causes for a higher score on the Penetration-Aspiration Scale in videofluoroscopy were intradeglutitive events that were not visible in swallowing endoscopy or false-positive events because of the loss of the lateral dimension in videofluoroscopy. A typical reason for a higher score on this scale in swallowing endoscopy was the better visualization of the anatomical structures. Narrow-band imaging in swallowing endoscopy resulted in a higher score on the Penetration-Aspiration Scale for liquids and semisolids in individual cases, although overall there was no statistically significant difference between scores using white light or narrow-band imaging.

CONCLUSIONS AND IMPLICATIONS

Videofluoroscopy and swallowing endoscopy may equally be considered as a diagnostic gold standard for oropharyngeal dysphagia regarding penetration, aspiration, and pharyngeal residue. Narrow-band imaging may increase the sensitivity for penetration and aspiration in individual cases.